The effects of salinity and temperature on the germination of the inland halophyte Hordeum jubatum

The roles of temperature and salinity in controlling the germination of Hordeum jubatum were investigated. Germination is inhibited by simulation of warm summerlike thermoperiods. Seeds of H. jubatum will germinate at the time of dispersal if exposed to a favorable temperature regime. Seeds germinate readily at salinities higher than those favorable to growth and reproduction. Thus, germination is not the life-cycle stage that limits the distribution of H. jubatum along a soil salinity gradient. This pattern differs from that of other species at the study site and from many other halophytes. The germination response to salinity and temperature is enhanced after a cold treatment. Storage conditions significantly alter the germination of H. jubatum seeds when exposed to a gradient of constant temperatures. Discrepancies between the results of previous germination studies with H. jubatum could be due to the differences in seed handling procedures.